U.S. patent number 10,491,042 [Application Number 15/145,185] was granted by the patent office on 2019-11-26 for wireless power transmission.
This patent grant is currently assigned to POWERMAT TECHNOLOGIES LTD.. The grantee listed for this patent is POWERMAT TECHNOLOGIES LTD.. Invention is credited to Ilya Gluzman, Elieser Mach.
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United States Patent |
10,491,042 |
Gluzman , et al. |
November 26, 2019 |
Wireless power transmission
Abstract
A system for wireless power transmission to an electronic
receiver placed in the vicinity of the system comprises a power
transmitter and at least one power repeater coupled to the power
transmitter. The power repeater is configured to repeat power
between the power transmitter and the receiver, wherein the power
repeater is tunable to a predetermined frequency, and wherein the
power repeater is configured to allow operation at a frequency
substantially equal to the frequency of the power transmitter.
Inventors: |
Gluzman; Ilya (Holon,
IL), Mach; Elieser (Rosh Tzurim, IL) |
Applicant: |
Name |
City |
State |
Country |
Type |
POWERMAT TECHNOLOGIES LTD. |
Neve Ilan |
N/A |
IL |
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Assignee: |
POWERMAT TECHNOLOGIES LTD.
(Neve Ilan, IL)
|
Family
ID: |
57223192 |
Appl.
No.: |
15/145,185 |
Filed: |
May 3, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20160329753 A1 |
Nov 10, 2016 |
|
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62156279 |
May 3, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02J
50/50 (20160201); H02J 50/12 (20160201) |
Current International
Class: |
H01F
27/42 (20060101); H02J 50/12 (20160101); H02J
50/50 (20160101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Chen; Sibin
Attorney, Agent or Firm: Dippert; William Greenberg;
Laurence Stemer; Werner
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional application
Ser. No. 62/156,279 filed May 3, 2015, the disclosure of which is
hereby incorporated in its entirety by reference herein.
Claims
The invention claimed is:
1. A system for wireless power transmission to an electronic
receiver placed in the vicinity of the system, the system
comprising: a power transmitter having a resonance frequency; and
at least one power repeater tuned to a resonance frequency
substantially different than the resonance frequency of the power
transmitter, wherein the at least one power repeater is coupled to
the power transmitter and is configured to repeat power from the
power transmitter to the power receiver, and wherein an operating
frequency of the power transmitter is slightly higher than the
resonance frequency of the repeater.
2. The system of claim 1, wherein the system comprises a plurality
of power repeaters, and wherein each power repeater is tuned to a
different resonance frequency.
3. The system of claim 2, wherein each power repeater is positioned
at a distance from the power transmitter, wherein the distance
provides optimal power transmission conditions.
4. The system of claim 2, wherein the power transmitter further
comprises a power supply configured to allow control of required
power for the power receiver.
5. The system of claim 4, wherein the power transmitter further
comprises a frequency controller configured to change the operating
frequency.
6. The system of claim 5, wherein the operating frequency is
controlled to be slightly higher than the different resonance
frequency of any power repeater of the plurality of power
repeaters.
7. The system of claim 5, wherein the power being transmitted is
controlled with amplitude modulation of the power transmitter.
8. The system of claim 5, wherein at least two power repeaters are
each coupled to the power transmitter simultaneously at
substantially different frequencies.
9. A method for wireless power transmission to an electronic
receiver, the method comprising: providing a power transmitter;
wirelessly repeating power between the power transmitter and the
electronic receiver; and controlling the power being transmitted by
changing the operating frequency of the power transmitter, wherein
the wirelessly repeating power is performed by at least one power
repeater, and wherein the operating frequency of the power
transmitter is tuned to be distinctively different from a pre-tuned
resonance frequency of the at least one power repeater.
10. The method of claim 9, further comprising performing pinging
within a frequency range of the corresponding at least one repeater
to stimulate a response in the power transmitter.
11. The method of claim 10, wherein the response changes according
to a position of the electronic receiver.
12. A repeater assembly for wireless power transmission from an
existing power transmitter to an electronic receiver placed in the
vicinity of the assembly, the repeater assembly comprising: at
least two power repeaters coupled to the power transmitter, and
configured to repeat power between the power transmitter and the
electronic receiver; and a housing configured to allow
accommodation of the at least two power repeaters, wherein the at
least two power repeaters operate at a frequency distinctively
different from a frequency of the power transmitter.
13. The repeater assembly of claim 12, wherein a lateral area of
the repeater assembly is substantially larger than a lateral area
of the power transmitter.
14. The repeater assembly of claim 12, wherein the at least two
power repeaters are coupled to the power transmitter
simultaneously, and wherein the power transmitter operates at two
substantially different frequencies.
Description
FIELD OF THE INVENTION
The present invention relates to wireless power transmission. More
particularly, the present invention relates to an improved system
and method for wireless power transmission using coupled
repeaters.
BACKGROUND OF THE INVENTION
Commercially available solutions for wireless power transmission
include inductive charging and also magnetic resonance techniques,
that differ mainly in their operating frequency ranges while having
very similar physical principals. In these solutions, an
electromagnetic field is generated at a transmitting coil with a
compatible receiving coil that is configured for the generated
field. Thus, power can be wirelessly transferred to the receiving
coil, via the electromagnetic field.
In order to increase the vertical range between the transmitting
coil and the receiving coil, power repeaters are sometimes used. A
power repeater is configured to operate in a predetermined
frequency compatible with the transmitting coil, such that power
can be wirelessly induced in the receiving coil from the repeater
instead of being directly induced from the transmitting coil.
The repeater is a passive element in the circuit, with the repeater
powered with induction from the transmitting coil. The magnetically
induced current in the repeater creates a magnetic field of its
own, such that this magnetic field of the repeater can be utilized
to induce current in the receiving coil. Thus, the passive
repeater(s) can be utilized to extend the active vertical range of
the power transmission. However, even with such repeaters it would
be advantageous to increase the lateral working range for the
wireless power transmission.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, a system for
wireless power transmission to an electronic receiver placed in the
vicinity of the system is provided, the system comprising: a power
transmitter; and at least one power repeater coupled to the power
transmitter, and configured to repeat power between the power
transmitter and the receiver, wherein at least one power repeater
is tunable to a predetermined frequency, and wherein at least one
of the at least one power repeater is configured to allow operation
at a frequency substantially equal to the frequency of the power
transmitter.
In some embodiments, at least one of the at least one power
repeater is also configured to allow operation at a frequency
distinctively different from the frequency of the power
transmitter.
In some embodiments, the at least one power repeater is positioned
at a distance from the power transmitter, this distance providing
optimal power transmission conditions.
In some embodiments, the power transmitter further comprises a
power supply configured to allow control of required power for the
receiver.
In some embodiments, the power transmitter further comprises a
frequency controller configured to allow changing the transmitted
power frequency.
In some embodiments, the frequency is controlled to correspond with
the frequency of the at least one power repeater.
In some embodiments, the frequency is controlled to correspond with
changes in the impedance of the at least one power repeater.
In some embodiments, the transmitted power is controlled with
change of the operating frequency.
In some embodiments, the transmitted power is controlled with
amplitude modulation of the power transmitter.
In some embodiments, at least two power repeaters are coupled to
the power transmitter simultaneously, and wherein the power
transmitter operates at two substantially different
frequencies.
According to a second aspect of the present invention, a method for
wireless power transmission to an electronic receiver is provided,
the method comprising: providing a power transmitter; wirelessly
repeating power between the power transmitter and the receiver; and
controlling the transmitted power by changing the operating
frequency of the power transmitter.
In some embodiments, the transmitted power is controlled with
amplitude modulation of the power transmitter.
In some embodiments, the transmitted power is further controlled in
accordance with the distance between the receiver and the power
transmitter.
In some embodiments, the wireless power repeating is performed by
at least one power repeater, and the method further comprises
positioning the at least one power repeater in a distance from the
power transmitter corresponding to provide optimal power
transmission conditions.
In some embodiments, the wireless power repeating is performed by
at least one power repeater, and the method further comprises
pre-tuning the at least one power repeater to distinctively
different frequency than the frequency of the power
transmitter.
In some embodiments, the method further comprises performing
pinging within the frequency range of the corresponding at least
one repeater to stimulate a response in the power transmitter.
In some embodiments, the response changes according to the
positioning of the receiver.
In some embodiments, the operating frequency of the power
transmitter is controlled to correspond with the frequency of the
wireless power repeating.
In some embodiments, the control of the transmitted power
corresponds to changes in the operating frequency of the power
transmitter.
According to a third aspect of the present invention, a repeater
assembly for wireless power transmission from an existing power
transmitter to an electronic receiver placed in the vicinity of the
assembly is provided, the repeater assembly comprising: at least
two power repeaters coupled to the power transmitter, and
configured to repeat power between the power transmitter and the
receiver; and a housing configured to allow accommodation of the at
least two power repeaters, wherein the at least two power repeaters
operate at a distinctively different frequency than the frequency
of the power transmitter.
In some embodiments, the housing is a plate with a thickness of 1
mm.
In some embodiments, the lateral area of the repeater assembly is
substantially larger than the lateral area of the power
transmitter.
In some embodiments, at least two power repeaters are coupled to
the power transmitter simultaneously, and wherein the power
transmitter operates at two substantially different
frequencies.
Unless otherwise defined, all technical and scientific terms used
herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. Although
methods and materials similar or equivalent to those described
herein can be used in the practice or testing of the present
invention, suitable methods and materials are described below. In
case of conflict, the specification, including definitions, will
control. In addition, the materials, methods, and examples are
illustrative only and not intended to be limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments are herein described, by way of example only, with
reference to the accompanying drawings. With specific reference now
to the drawings in detail, it is stressed that the particulars
shown are by way of example and for purposes of illustrative
discussion of the preferred embodiments, and are presented in the
cause of providing what is believed to be the most useful and
readily understood description of the principles and conceptual
aspects of the embodiments. In this regard, no attempt is made to
show structural details in more detail than is necessary for a
fundamental understanding of the invention, the description taken
with the drawings making apparent to those skilled in the art how
the several forms of the invention may be embodied in practice.
In the drawings:
FIG. 1 schematically illustrates a circuitry for a wireless power
transmission system, according to an exemplary embodiment.
FIG. 2A shows a voltage vs. frequency graph of a primary coil
coupled to first and second repeaters, according to an exemplary
embodiment.
FIG. 2B shows a current vs. frequency graph of the primary coil
coupled to the first and second repeaters, according to an
exemplary embodiment.
FIG. 3 schematically illustrates a repeater assembly positioned
over an existing infrastructure with a primary coil, according to
an exemplary embodiment.
FIG. 4 shows a flow chart for controlling the power transmitted
from the transmitter to the receiver, according to an exemplary
embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before explaining at least one embodiment in detail, it is to be
understood that the invention is not limited in its application to
the details of construction and the arrangement of the components
set forth in the following description or illustrated in the
drawings. The invention is capable of other embodiments or of being
practiced or carried out in various ways. Also, it is to be
understood that the phraseology and terminology employed herein is
for the purpose of description and should not be regarded as
limiting.
For clarity, non-essential elements were omitted from some of the
drawings.
FIG. 1 schematically illustrates a circuitry for a wireless power
transmission system 1000, with a repeater assembly 150. A primary
resonant tank circuit 100 has a primary capacitance Cp 11 and a
primary inductance Lp 12. If a power source 110 is provided to the
primary resonant circuit 100, then a desirable electromagnetic
field may be created in order to induce magnetic flux through
auxiliary coils in the vicinity of the primary transmitting
resonant circuit 100. By positioning the repeater assembly 150 near
the electromagnetic field created by the transmitting resonant
circuit 100, the primary circuit 100 may be coupled to a first
repeater 120, and also to a second repeater 140. It should be noted
that in an exemplary embodiment, for simplicity the repeater
assembly 150 comprises two passive repeaters, while additional
repeaters may also couple to the primary circuit 100. Preferably,
the repeater assembly 150 has an area larger than the primary
circuit 100 and comprises four passive repeaters.
In a preferred embodiment, at least two passive repeaters are
provided as adjacent coils embedded in a thin plate, with plate
thickness of about 1 mm (for instance as shown in FIG. 5). Such a
plate may be simply placed over the transmitting primary circuit in
order to increase the lateral range of the primary circuit through
the passive repeaters, further described hereinafter.
The first repeater 120 has a first capacitance C1 13 and a first
inductance L1 14. Similarly, the second repeater 140 has a second
capacitance C2 15 and a second inductance L2 16, wherein the
capacitance and/or inductance of the first and second repeaters
120, 140 may be configured to allow optimal power transmission.
Each repeater is magnetically coupled to the primary transmitting
resonant circuit 100 with some coupling coefficient 0<k<1
(whereby each repeater has its own coupling coefficient). The
coupling coefficient "k" represents the degree of inductive
coupling between a transmission coil and a reception coil, wherein
the coupling coefficient "k" may be varied according to the
relative position and distance between the transmission coil and
the reception coil (for instance a repeater). In some cases,
working with two coupling coefficients (e.g. from transmitter to
repeater, and from repeater to receiver) may provide higher
efficiency when compared to working without repeaters with similar
distances.
Additional coils (for instance a wireless power receiver coil,
possibly embedded in a rechargeable electronic device such as a
smartphone) may then couple to the first repeater 120 and/or the
second repeater 140 and thus inductively receive power to be
charged or powered. Optionally, the second repeater 140 is in turn
induced from the first repeater 120 (thus increasing the distance
from the second repeater to the primary coil), such that any
additional coil may be induced in a greater distance from the
transmitting coil.
An exemplary second coil 200 has a secondary capacitance Cs 17, a
secondary inductance Ls 18, and also a load 19. It is appreciated
that by predetermining all of these parameters Cp, Lp, C1, L1, C2,
L2. Cs, Ls, the power transmission may be controlled when the
transmitter, receiver, and repeaters are placed at suitable
distances such that corresponding coupling coefficients may allow
the required power transmission.
It should be noted that with repeater setting, the auxiliary coil
200 need not be connected to any power supply since power is drawn
by the inductors (i.e. first and/or second repeater 120, 140) from
the primary circuit 100 alone.
FIG. 2A shows a simulation of a voltage vs. frequency graph of a
primary circuit 100 coupled to first and second repeaters 120, 140.
A first curve 21 corresponds to the primary transmitting coil 100.
A second curve 22 corresponds to the first repeater 120, and a
third curve 23 corresponds to the second repeater 140.
Generally, these curves (of a single transmitter and two repeaters)
have three peaks 10, 20, 30. A first peak (.about.110 kHz)
corresponds to the resonance frequency of the primary circuit 100.
A second peak (.about.270 kHz) corresponds to the coupling of the
primary circuit 100 to the first repeater 120. A third peak
(.about.430 kHz) corresponds to the coupling of the primary circuit
100 to the second repeater 140. It should be noted that these
curves do not show the induced self-resonance of additional
receivers.
At the first peak 10, the first curve 21 is dominant At the second
peak 20, the second curve 22 is dominant At the third peak 30, the
third curve 23 is dominant
FIG. 2B shows a simulation of a current vs. frequency graph of a
primary circuit 100 coupled to first and second repeaters 120, 140.
Similarly to the voltage graph shown in FIG. 2A, here the current
graph has a first curve 31 corresponding to the primary
transmitting circuit 100. A second curve 32 corresponds to the
first repeater 120, and a third curve 33 corresponds to the second
repeater 140.
These curves also have three peaks 10, 20, 30. At the first peak
10, the first curve 21 is dominant At the second peak 20, the
second curve 22 is dominant At the third peak 30, the third curve
23 is dominant
It should be noted that the abovementioned values in the graphs
(shown in FIGS. 2A-2B), are exemplary and correspond to a
particular simulation. However, the same operation may be achieved
with this system having different values. For example, changing the
capacitance of the primary circuit such that the resonant tank may
operate in a different frequency. Therefore, similar behavior of
these curves (of a single transmitter and two repeaters) may be
achieved for different wireless power transmission techniques, such
as the inductive charging and also magnetic resonance
techniques.
It is appreciated that working with frequencies below the .about.7
Mhz resonance frequency, prevents the abovementioned system from
interacting with household metals (e.g. coins in the pocket of a
user) that may interfere with the operation of the system.
A frequency controller (not shown in the figures) may be coupled
with the primary transmitting circuit 100 in order to utilize the
coupling to the repeaters (as may be appreciated from FIGS. 2A-2B).
The first and second repeaters 120, 140 may then be pre-tuned to
distinctively different frequencies than the resonance frequency of
the primary circuit 100. Preferably, the primary circuit 100
resonates at a significantly lower frequency than the predetermined
resonance frequency of the repeaters 120, 140. Optionally, the
resonance frequencies of the system may be determined by adjusting
the capacitance and/or inductance of the different components in
the system.
In such a configuration, the passive repeaters 120, 140 are driven
by the "tail" of the resonance curve of the primary coil 100.
Namely, due to the coupling of the primary circuit 100 to the
repeaters 120, 140, two peaks are created as a "tail" for the
frequencies of the repeaters (see peaks 20, 30 in FIGS. 2A-2B).
In case that the first and second repeaters 120, 140 are configured
to have a high quality factor (as shown in FIGS. 2A-2B) and also a
compatible coupling coefficient, then the repeaters 120, 140 may
drive sufficient energy in order to support charging through them
by auxiliary coils, due to the coupling with the primary coil,
wherein the frequency may be controlled with the frequency
controller. It is appreciated that while the simulation (shown in
FIGS. 2A-2B) describes a repeater assembly with two repeaters, a
similar simulation may easily be performed for additional
repeaters. For example, a repeater assembly with four
repeaters.
In order to control the power transmitted through a repeater to a
receiver, the impedance of the repeaters may be used. Initially,
the impedance of the repeater may be used in order to detect
possible placement of a receiver in the vicinity of the repeater.
This may be performed with "analog pings" in some frequency within
the frequency range of the corresponding peak of the repeater (for
instance the peak 30 of the second repeater, as shown in FIGS.
2A-2B). Such analog pinging may stimulate a response in the
transmitting circuit, whereby the response changes according to the
placement of the receiver. This change occurs due to changes in the
impedance of the repeater. Optionally, the inductance of the
repeater may also change accordingly.
Furthermore, the transmitted power may also be controlled by
varying the operating frequency (within the frequency range of the
repeater's resonant peak). Operating at a frequency higher and/or
lower than the resonant frequency of the repeater may decrease the
transmitted power and vice versa. Preferably, the operating
frequency is above resonance. The control of the transmitted power
may also be done in other ways (for instance amplitude modulation,
duty cycle modulation, changing the characteristics of the
receiver, etc.).
Thus, since a repeater coupled to a receiver may have
distinguishable impedance, then such a repeater may be recognized
by the primary circuit. Once a particular repeater is recognized,
the primary circuit may begin transmitting in the frequency domain
of that particular repeater (using the frequency controller). This
is in contrast to commercially available solutions, where all coils
and repeaters have substantially equal frequencies as they only aim
at increasing the vertical distance.
The induced magnetic flux generated at the repeater may be
sufficient for the additional coil 200 and therefore provide
enhanced lateral range of operation since there's no longer the
limitation of the primary coil and repeaters operating in a single
frequency at a short distance. Specifically, instead of being
forced to place a device with the additional coil (e.g. a Bluetooth
earpiece) precisely at the central point of the primary coil, it is
now possible to place a repeater assembly over the primary coil
such that the lateral range for positioning the additional coil
increases due to the extended range provided by the repeater
assembly. For example, increasing from a 7 cm lateral range with
the primary coil to a 13 cm range with the repeater assembly.
Optionally, in addition to an increase in the lateral range, the
vertical range for wireless power transmission also increases.
Furthermore, it may be possible to use existing infrastructure
(e.g. charging spots at coffee shops) with additional passive
repeaters such that the entire range is extended, whereby only
minor adjustments may be required. For example, placing a repeater
assembly over a table having an existing built-in charging
spot.
It is appreciated that the abovementioned graphs (shown in FIGS.
2A-2B), are shown for one configuration of the wireless power
transmission system 1000, specifically for the inductive coupling
configuration operating in lower frequencies (<1 MHz). With
appropriate adjustments to the system 1000, similar behavior may be
achieved for the magnetic resonance configuration operating in
higher frequencies (.about.7 MHz).
In a further embodiment, a different number of repeaters are used
in the system. Using the same principle, additional repeaters may
further increase the operational range of the power transmission.
Optionally, only a single repeater may be used.
FIG. 3 schematically illustrates a repeater assembly 150 positioned
over an existing infrastructure with a primary coil 100 (e.g.
built-in in a table 50). With commercially available solutions, if
the repeater assembly 150 was not present, then the auxiliary coil
200 is forced to be positioned directly over the primary coil 100
in order to receive wireless power transmission due to the limited
range of the electromagnetic field. However, by simply placing the
repeater assembly 150 (for instance comprising four passive
repeaters) over the primary coil 100 then the range for induction
increases and it is now possible to position the auxiliary coil 200
near a repeater and not necessarily over the primary coil 100.
If the repeater assembly 150 is placed over the primary coil 100,
then a user interested in wirelessly powering a device with a
compatible auxiliary coil 200 may move the auxiliary coil 200 to be
near the repeater assembly 150. In a preferred embodiment, the
system identifies which repeater in the repeater assembly 150 is
closest to the auxiliary coil 200 and the frequency of the primary
coil 100 may then be adjusted by the frequency controller (not
shown) to couple with the nearest repeater (e.g. the second
repeater 120). For example, the primary coil 100 may start
operating in a frequency slightly higher than the frequency of the
second repeater 120 that is nearest to the auxiliary coil 200 such
that the auxiliary coil 200 may receive power from the repeater
instead of receiving power directly from the primary coil 100.
In a further embodiment, the system may comprise active repeaters
that can change the operating frequency to the same frequency
domain by themselves, instead of the primary coil changing the
frequency. Thus, a receiver with large or multiple "pick-up" coils
in the same frequency domain may use a superposition of more than
one repeater. Optionally, such active repeaters may operate in the
same frequency domain but are also used simultaneously from a
lateral point of view, therefore providing simultaneous
transmission.
In a further embodiment, in order to cover a large area multiple
such systems may be utilized, wherein each system has a primary
coil and a repeater assembly. Thus, a user may place an auxiliary
coil such that at least one primary coil may transfer power to it.
For example, a long table with multiple primary coils, whereby each
primary coil is equipped with a repeater assembly.
In a further embodiment, the system may be provided as a single
unit with the primary coil in the centre and multiple passive
repeaters surrounding the primary coil. Alternatively, the system
may be provided as a single unit with the repeater assembly fixed
adjacent to the primary coil, instead of providing a plate (with
repeaters) that needs to be positioned over the primary coil.
In a further embodiment, the primary coil may operate in at least
two different frequencies simultaneously, for instance a high
frequency (.about.7 MHz) and a low frequency (.about.1 MHz). Thus,
it may be possible to induce more than one repeater at the same
time. This may be required to power an auxiliary coil with multiple
repeaters, and/or to power multiple auxiliary coils with multiple
repeaters. For example, powering a first auxiliary coil with a
first repeater and powering a second auxiliary coil with a second
repeater operating at a different frequency.
In a further embodiment, using multiple tuneable repeaters, several
devices may be detected near the repeater assembly. Then at least
one repeater may be tuned to a frequency substantially equal to the
frequency of the power transmitter thereby extending the range of
the power transmission, whereby the other repeaters may operate off
resonance. Thus, the repeaters which are tuned to the relevant
frequency (i.e. of the frequency of the transmitter) may resonate
and power all of the detected devices while the other repeaters may
remain "silent" (as they operate off resonance). Optionally, in
this configuration each repeater powers a single device. It is
appreciated that such a feature may prevent the heating of
household metallic objects placed on the same surface, since the
repeaters not coupled to the detected device are "silent" and
therefore do not transmit. This can be specifically important in a
restaurant (or coffee-shop) environment where metallic objects
(e.g. forks, etc.) are likely to be placed in the vicinity of the
repeater assembly, for example as a plate on the table.
FIG. 4 shows a flow chart for controlling the power transmitted
from the transmitter to the receiver. In a system with a
transmitter and at least one repeater, initially the power supply
is activated 41. Then power may be induced in the at least one
repeater from the transmitter 42 Finally, the system may be ready
for power transmission 40, whereby the at least one repeater may be
pre-tuned to a distinctively different frequency than the resonant
frequency of the transmitter 43.
Next, a receiver may be placed in the vicinity of the at least one
repeater 44. If analog pinging is performed within the frequency
range of the corresponding peak of the at least one repeater, then
a response is stimulated in the transmitter 45 (for the
corresponding repeater). Once the corresponding repeater is
detected, the transmitter may transmit in the frequency domain of
the corresponding repeater 46 Finally, the transmitted power
corresponding to the receiver may be controlled 47.
It is appreciated that certain features of the invention, which
are, for clarity, described in the context of separate embodiments,
may also be provided in combination in a single embodiment.
Conversely, various features of the invention, which are, for
brevity, described in the context of a single embodiment, may also
be provided separately or in any suitable sub combination.
Although the invention has been described in conjunction with
specific embodiments thereof, it is evident that many alternatives,
modifications and variations will be apparent to those skilled in
the art. Accordingly, it is intended to embrace all such
alternatives, modifications and variations that fall within the
spirit and broad scope of the appended claims.
* * * * *